Electric switch for fire-alarms.



e. w. DEWITT.

ELECTRLC SWITCH FOR FIRE ALARMS. APPLICATION FILED MAR. 39, 1918.

1 ,300, 1 34, Patent-ed Apr. 8, 1919.

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, Gemgge W176 GEORGE W. DE WITT, 0F FENTON, MICHIGAN.

ELECTRIC SWITCH FOR FIRE-ALARMS.

Specification of Letters Patent.

Patented Apr. 8, 1919.

Application filed March 30, 1918. Serial No. 225,714.

To aZZ "whom it may concern:

Be it known that I, GEORGE W. DE WITT, a citizen of the United States, residing at Fenton, in the county of Genesee and State of Michigan, have invented certain new and useful Improvements in Electric Switches for Fire-Alarms; and do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others, skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, andto the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in automatic circuit closing devices for use in giving alarms, in case of fires and consists of a simple and efficient device of this character having various details of construction, combinations and arrangements of parts which will be hereinafter fully described, shown in the accompanying drawings and then specifically defined in the appended claim.

My invention is illustrated in the accompanying drawings which, with the letters of reference marked thereon, form a part of this specification and in which:

Figure 1 is a side elevation showing the application of my invention to a bell.

Fig. 2 is an enlarged sectional view longitudlinally through the circuit closing device, an

Fig. 3 is an enlarged plan view of the circuit closing device with weight attached.

Reference now being had to the details of the drawings by letters:

A designates a plate of suitable insulation material which may be placed at any location where a fire is likely to take place, such as adjacent to fiues or heaters of different kinds, and mounted upon said plate are two wires, designated respectively by letters D and E, the former being bent to form an eye F midway its length, and each wire is bent to form a loop H. to which the two wires K and L respectively are connected, as shown in Fig. 1 of the drawings and which lead to terminals 0 of the alarm bell. A weight, designated by letter R, is fastened to a cord or rope T of inflammable material, said weight being adapted to overcome the tension of the wire D, the latter being of a resilient material, and when the weight R is released from the cord T which is attached to the wire, the latter will contact with the terminal E, close the circuit and cause the bell to ring.

Pins S project from said plate and against which the wire D is adapted to contact to limit its outer throw.

In adjusting the device the circuit closing means may be concealed within the wall, or positioned wherever a fire is likely to occur, and when the heat is sufficient to burn the cord, the alarm will be automatically sounded. If desired, a plurality of the circuits may be positioned at various locations, connected to a single alarm or to several alarms.

What I claim to be new is:

A circuit closing device for alarms, comprising a plate of insulation material, a stationary wire fastened thereto and terminating at one'end in an eye and its other end outwardly curved, a second wire fastened at one end to said plate and resilient, bent at its longitudinal center to form an eye, and having a free end held normally by the resiliency of the saine in contact with the curved portion of the first referred to wire, pins projecting from the plate, one upon either side of the eye formed at the longitudinal center of said resilient wire, and serving to limit the outer throw of the latter,

an inflammable cord connected to the eyeof the resilient wire, and a to said cord.

In testimony whereof I hereunto aifix my signature in presence of two witnesses.

GEORGE W. DE WITT.

Witnesses:

EMERSON M. NnwnLL, DENNIS E. KnLLnHnR.

weight fastened copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patentswoshinlton, D. 0. 

